Energy balance process for the pulp and paper industry

Abstract

The process described is a novel use of two complementary processes, the first of which provides the product to be converted into energy by the second process, related in such a way that the two combined provides an alternative to conventional fuels at a significant economical advantage. Specifically, the burning of sulfur with air or oxygen produces sulfur dioxide which can be combined with water to form sulfuric acid and by electrolysis, the sulfuric acid and water is converted to hydrogen gas. Hydrogen gas is burned as has been the sulfur, each producing thermal energy which is used to produce steam. The steam produced by burning the two fuels, sulfur and hydrogen gas, is used in the pulp mill in exactly the same manner as has been steam produced by burning fuels such as natural gas, fuel oil, coal and wood.

It is therefore claimed for this patent as follows: 
     
       1. A pollution free process for the production of steam and energy by the burning of sulfur and an electrolysis of the by-products of burning sulfur mixed with water comprising the steps of: burning a requisite amount of sulfur in a sulfur burner to produce hot combustion gas and sulfur dioxide; passing said hot combusion gas and said sulfur dioxide directly through a waste heat boiler in addition to water provided from a source and utilizing the heat exchange between said hot combusion gas, said sulfur dioxide, and said water to produce steam, cooled sulfur dioxide, and cooled combustion gases; passing said cooled sulfur dioxide while supplying water to a closed scrubber used only to mix said cooled sulfur dioxide with said supplied water to provide a constant feedstream of about 90% sulfur dioxide and about 10% water without losing any sulfur dioxide to the environment; passing said feedstream to an absorption tower while supplying additional water to obtain a mixture of about 49% sulfur dioxide and sulfuric acid; passing said mixture into a sulfur dioxide electrolysis unit to produce hydrogen and by-products consisting of a second mixture of sulfur dioxide and sulfuric acid; burning said hydrogen produced in said process to further produce energy in the form of steam or for use as direct heat. 
     
     
       2. A steam and energy production process according to claim 1, further comprising the steps of: recycling said second mixture through a sulfur dioxide separator to separate said second mixture into separated sulfur dioxide and separated sulfuric acid; supplying said separated sulfur dioxide to said absorption tower for cycling through said electrolysis unit; passing said separated sulfuric acid to an acid concentrator while utilizing waste heat from a pulp mill or the like to concentrate said separate sulfuric acid for use.